Services that allow content data such as movies (motion pictures) or music to be distributed via the Internet are widely available. Recently, in particular, progressive download services are in actual use associated with improvement in high-speed network access so that image data can be played back concurrently while downloading the data in large volume storage devices of information processing devices.
Communication technology using the PeertoPeer (P2P) model as an architecture for communicating between a large number of users is receiving attention. Characteristically, the P2P model allows direct access to a terminal of an ordinary user from terminals of other users. The advantage is that, as compared with the client server model in which a server is loaded with heavy traffic, communication continues to be available even if the number of terminals grows enormously so long as sufficient circuit bandwidth is allocatable. Recently, services that allow content data to be distributed in the P2P model have been in actual use.
Details of certain know systems and devices may be found in U.S. Pat. No. 6,563,999.
In real world situations, friends may go to a film theater together or get together in the home one of them to watch a movie. By watching a movie with friends, people can share the impression they felt and can enjoy the movie more than otherwise. In arranging such an event, however, people often experience difficulty in schedule adjustment. It is particularly difficult for friends at remote locations to join. It will be desirable in this respect to build a virtual film theater and provide an environment in which a plurality of persons can share the impression they felt.
In this background, the present invention provides a technology of playing back content data in synchronization between a plurality of information processing devices.